To Sam Hui Pui-to, hepatitis B was a death sentence. At the peak of his health when he was a fireman, he set records in firefighters' fitness tests.
The diagnosis in 2003 so shattered him that he tried to take his own life, thinking the illness would kill him anyway if he could not get a liver transplant in time.
He gave up the suicidal thoughts only because he did not even have the strength to open the window in the hospital ward, much less jump out of it.
Nine years on, Hui has recovered. Now 52, he is taking part in the 100-kilometre fund-raising Oxfam Trailwalker next month.
He is teaming up with a liver donor and two doctors to raise awareness of liver disease, get more people to sign up as organ donors and urge patients not to give up on life.
Hui recalled that devastating period, when he was transformed from a top fireman - capable of doing 700 sit-ups non-stop - to a disease-wrecked man with no energy to kill himself.
"Fortunately, I received a liver transplant after a wait of only two months and I survived," he said.
"By taking part in this hiking event, I want to tell liver patients that they need to be strong for their families."
He left the Fire Services Department two and a half years ago and is a martial arts consultant for television shows and movies.
Joining Hui on the Oxfam Trailwalker are Commercial Radio DJ "Little Master Law" Hui Yiu-pun, 30, and Queen Mary Hospital associate consultants William Sharr Wei, 40, and Dai Wing-chiu, 34, both of whom specialise in liver transplants.
DJ Hui, who studied law at Hong Kong University, said he donated part of his liver to his mother in 2009 because she had liver cancer.
"My mother's ordeal has led me to realise that everyone has to treasure the time they have with their family," he said.
The Oxfam Trailwalker will take place from November 16 to 18. A total of 1,200 teams, comprising 4,800 participants, have 48 hours to walk over 20 hills, mainly along the MacLehose Trail, from Pak Tam Chung in Sai Kung to the Po Leung Kuk Jockey Club in Yuen Long.
Oxfam hopes to raise HK$300 million.